How to add 2 letter language code in ISO 639-1

Mark Davis ☕️ mark at
Tue Feb 28 14:58:02 CET 2017

While that is an accurate response, it isn't the whole response. Even if
ISO 639-1 were to add a two letter code:

   In order to avoid instability in the canonical form of tags, if a
   two-character code is added to ISO 639-1 for a language for which a
   three-character code was already included in either ISO 639-2 or ISO
   639-3, the two-character code MUST NOT be registered.  See
   Section 3.4 <>.

That means that such a 2 letter code would not be used by BCP47, which
means it would effectively be pointless for language tagging. Most industry
has shifted to using BCP47 as the source for codes for language, territory,
etc, since they provide the stability that ISO doesn't.


On Tue, Feb 28, 2017 at 2:19 PM, Arthur Reutenauer <
arthur.reutenauer at> wrote:

>         Hi Saroj,
>   This discussion list is not responsible for the various ISO standard
> code sets; we only monitor the changes in ISO standards to reflect them
> in the language subtag registry (
> assignments/language-subtag-registry).
> The institution responsible for maintaining ISO 639-1 is Infoterm
> (, you can
> try and contact them but it is unlikely that they will consider new
> codes for adoption.  I don’t know what the exact criteria are but it is
> very, very rare that codes are added to ISO 639-1.  There are a few
> hints about what the criteria are on the website of the US Library of
> Congress that is the maintenance agency for ISO 639-2
> (
>         Best,
>                 Arthur
> _______________________________________________
> Ietf-languages mailing list
> Ietf-languages at
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